Today is the Optional Memorial of St. John of Capistrano (1386-1456). John was a native of Capistrano, in Italy. He became a Franciscan and was one of the great organizers of the struggle against the Mohammedans in the 15th century, when they threatened to overrun the whole of Europe. Mohammed II had taken Constantinope and was already marching against Belgrade, when Pope Callixtus III called St. John to preach the crusade; assisted by the Hungarian John Hunyadi, he gathered a strong Christian army, which defeated the Turks in the great battle of Belgrade (1453). He died in 1456.